1. Field of the Invention
The invention presented herein relates to the field of electrographic stylus recording apparatus capable of producing a toner powder image on a receptor member and, more particularly, to the structure providing for return to the toner powder hopper of the apparatus that toner powder which is presented for imaging but is not used as a part of the toner powder image.
2. Description of the Prior Art
U.S. Pat. No. 4,460,907 issued July 17, 1984 to Kerry S. Nelson discloses an electrographic magnetic stylus recording apparatus capable of producing an unfixed or nonpermanent toner powder image on a receptor belt. A stylus array is positioned adjacent to the receptor belt to provide a recording gap. Toner powder is provided to the recording gap as the receptor belt is moved. A toner powder image is formed in accordance with electrical signals selectively applied to the styli of the stylus array. Since the toner powder image that is formed is unfixed or nonpermanent, the apparatus provides for reuse of the toner powder. Toner powder that is not held on the receptor belt as a part of the toner image by an electrical charge is collected and returned by gravity to the portion of the apparatus where toner is supplied to the receptor belt for movement to the recording gap. The use of gravity as a part of the toner return or recirculation arrangement limits the configuration of an electrographic magnetic stylus recording apparatus for providing a toner powder image. Further, it is important to minimize the abrasive action to which the toner powder is subjected to lengthen the useful life of the toner powder in the case of apparatus providing an unfixed toner powder image where the toner powder is reused.